[Goldfish2]

Hello all,

I have a Fanuc 6mb controlled machine that is creating a 401 Servo Alarm (OVC) on the Z axis. I checked the oil meter unit and it is oiling. The head moves up and down fine with motor disconnected which leads me to believe that I have an issue with the internal brake, but I don't know exactly how to adjust it, or where it is in the motor. That is where I am looking for some assistance for now.

The Z axis motor is Series 10m part number A06B-0651-B212.
Standard Specs are as follows


A06B-0651-B212 Fanuc DC Series M Model 10 Axis Motor with BRAKE. This motor is rated as the following: 12Nm TRQ, 12 Amp, 2 phase 165V 1200 RPM motor, this motor is a straight shafted motor fitted with a brake and 2000 pulse black encoder.

Thanks.

Brent

[PEGBOARD]

At what point does the Alarm occur?
It could be something as simple as bad contacts on a relay depending at what point the the machine Alarms out.

[Goldfish2]

Hi Pegboard,

A little update from tonight....

I made a mistake on my initial post info... the Pulse is actually 2500 and the RPM is 1500.... motor series, other info, etc was good on the original post though.

On the motor... I disconnected it from the ball screw, I then jogged it under power whilst it was still connected to the machine electrically via the connectors and it makes a slight screeching sound.

That being said, I temporarily hooked up another motor, same type, version, pulse coder, etc... (one that was laying around from another machine we are planning on getting running.) It did not alarm out in the freewheeling mode. (aka disconnected from ball screw mode).... It also did not make that screeching sound... which I assume to be the brake on the other motor.

[Goldfish2]

Also @Pegboard it alarms out when connected to the ballscrew, etc... under small jogs, or large... it is random seemed like stick slip, but it wasn't because the head moves up and down okay with motor disconnected. ( I assume the brake is the issue, I got this idea from the screeching sound that occurred when freewheeling the axis motor while it was disconnected from the ball screw.) That is actually what I was hoping for ironically... a Motor Issue, vs. a Way Issue, etc.

[PEGBOARD]

Hi. yes it certainly looks like an issue with the Motor, as for trying to repair or adjust it I would leave it to the "experts" and send it for repair. Here in the UK its easy to get a Fanuc Motor serviced and doing a quick google there are a few on the web.

[peloflex]

Hello guys! Do you know by any chance, what is the voltage required to activate this motor brake that you are talking about? I can´t seem to find this info in the machine´s manual. I am having the same error with our Z axis, but I need to make sure that the brake is getting its nominal voltage and if that checks ok, then I will proceed to take the motor appart and check the nominal 0.06mm gap/clearance on the brake.